1. Field of the Invention
The present invention relates to silver halide emulsions spectrally sensitized by novel merocyanine dyes and particularly to silver halide photographic emulsions having high green sensitivity.
2. Description of the Prior Art
Hitherto, as spectral sensitizers for photographic emulsions, it has been known to use certain dimethine merocyanine dyes as described in, for example, U.S. Pat. Nos. 3,480,439, 3,501,306, 3,567,458, 3,625,698, 3,698,910, 3,736,145, 3,765,900, 3,765,901, and 4,057,430, Japanese Patent Publication Nos. 18105/71 and 549/71, German Pat. No. 1,234,522 and British Pat. No. 800,244, etc. However, silver halide photographic sensitive materials containing these known dimethine merocyanine dyes often suffer stains, deterioration of sensitivity with a lapse of time or increase fogging.